No casualties reported but streets of the Old City submerged by floodwater.

Floods have hit Yemen's capital Sanaa less than a week after severe thunderstorms caused flash flooding in the city's suburbs.

On Wednesday the streets of the Old City were submerged by floodwater but there were no reports of any deaths.

Sanaa is one of the oldest continually inhabited cities in the world. It lies at an elevation of 2,300 metres, which means that it remains relatively cool there throughout the year, avoiding the extreme heat of much of the rest of the Arabian Peninsula.

Although Sanaa's climate is classed as "semi-arid desert", it does experience a relatively high annual rainfall of 240 millimetres.

Much of this falls during the July and August period, and it is generated by convective clouds which develop as warm, moist air from the southwesterly monsoon rises over the mountains.

This process is at its peak during August with a typical monthly rainfall total of 95mm.

The intense nature of the summer rainfall is exacerbated by the poor infrastructure in the city which has been made worse by the ongoing war.

Rapid runoff of floodwater also elevates the risk of diseases such as cholera which is a major problem across this war-torn country.

Save the Children reported that more than 400,000 people have contracted the disease since an outbreak began in April 2015. As many as 1,900 people, including children, have died.

The risk of showers, some of them heavy enough to cause further flooding, is expected to continue for at least the next week.